1. Field of the Invention
The present invention relates generally to computer networks and their management. More particularly, it relates to discovery of network elements and determining their connectivity.
2. Description of Related Art
Computer networks provide communication paths between various machines (e.g., workstations, printers, servers) in the network. A local area network (LAN) (also known as a campus) is a computer network that spans a relatively small area. A wide-area network (WAN) is a network of LANs.
Information sent from one machine in a network to another is typically sent through some interconnect device. These devices amplify and/or route traffic within the network. Interconnect devices include, e.g., switches, routers, bridges and repeaters.
A node is a processing location in a network. A node can comprise various machines such as, e.g., workstations, servers or printers physically linked to a network interconnect device.
As used herein, a network “element” can comprise various network devices including interconnect devices and network nodes.
Keeping track of all of the nodes in a network is difficult, particularly when the network is fast growing or changing, i.e., network nodes are being quickly added or changed. In a very short LAN, a network administrator might be able to physically trace the cable of the network to determine which nodes are located on the network and how they are connected. However, LANs can extend some distance and through many floors and offices within a building, making physical tracing typically virtually impossible.
There are known methods of automatically determining network topology such as, e.g., the automatic discovery processes disclosed in U.S. Pat. No. 5,185,860 and U.S. Pat. No. 5,727,157. Determining network topology typically includes two steps: (1) discovering individual network elements; and (2) determining their connectivity.